Performance of the IMMY® sona Aspergillus lateral flow assay for the detection of galactomannan in tracheal aspirate samples from Brazilian patients with COVID-19-associated pulmonary aspergillosis: Cross-sectional and systematic review of literature

During the COVID-19 pandemic, many patients in intensive care units (ICUs) were affected by invasive fungal infections, including aspergillosis, contributing to a high mortality rate. Diagnosing proven COVID-19-associated pulmonary aspergillosis (CAPA) requires clinical and radiological evaluations, along with laboratory testing of bronchoalveolar lavage samples or lung biopsies. However, these procedures and equipment are often inaccessible in developing countries or regions with limited resources, including Brazil. Consequently, alternative diagnostic methods, such as measuring Aspergillus galactomannan (GM) in tracheal aspirate (TA), have been explored for CAPA diagnosis. Nonetheless, research on the efficacy of TA-based diagnostic tests is limited. This study aimed to assess the performance of the IMMY® Sona Aspergillus lateral flow assay (LFA) for GM detection in TA samples from 60 ICU patients with suspected CAPA at two tertiary hospitals in Campo Grande, Brazil. The ELISA method (Platelia Aspergillus AG, Bio-Rad®) was used to detect Aspergillus GM in TA samples, serving as the microbiological criterion and reference test. Fifteen patients (12.4%) were identified as having possible CAPA. The overall accuracy of LFA was 94%, and the tests demonstrated an agreement of 93.1% (Cohen's kappa of 0.83). Based on our findings, the LFA for Aspergillus GM detection in TA samples exhibited excellent performance, proving to be a valuable diagnostic tool for potential CAPA. In a systematic review, two studies were included, and the meta-analysis revealed pooled estimates provided a sensitivity of 86% (95% CI, 80%-91%) and specificity of 93% (95% CI, 86%-97%). The diagnostic odds ratio (DOR) for identification of Aspergillus using LFA was 103.38 (95% CI, 38.03-281.03). Despite its lower sensitivity compared to our study, the LFA appears to be a promising diagnostic option for CAPA, particularly in suspected cases that have not received antifungal therapy. This enables timely antifungal treatment and could reduce mortality rates in regions where bronchoscopy is unavailable or limited.